The present invention relates generally to the loading and unloading of bulk tankers and more particularly to a valve assembly with flush and sample capability for maintaining chemical purity of the material to be loaded or unloaded.
The need exists in the electronic semiconductor chemical business to load and unload high purity chemicals into bulk road tankers (e.g., 3,000 to 8,000 gallons) and rail tankers (e.g., 10,000 to 20,000 gallons) under conditions that maintain chemical purity and worker safety, while preventing spillage into the environment. Moreover, it would be convenient also to obtain samples for chemical certification prior to the loading/unloading procedure again while preventing spillage into the environment and without contaminating the chemical being loaded/unloaded.
Presently, a sample valve is bolted to 2-inch flange connections and the tanker is pressurized to obtain a sample upstream of the flange connection for certification. The tanker fill valve then is opened to permit loading/unloading. This method will contaminate the chemical being transferred at the point of connection and is a safety issue and environmental concern with operating personnel disconnecting the flanged flex hose assemblies with chemical residue after chemical transfers.
Thus, there exists a need in the art to be able to environmentally safely transfer high purity chemicals while being able to sample with chemical for chemical purity without risking its contamination. Such need is addressed by the present invention.